Extractor fans for shed

[mark56789]

Hi everyone!

I'm considering setting up two 12v extractor fans in a damp shed to prevent mould - one fan sucking in air from outside and another fan positioned on the opposite wall extracting the air. The shed doesn't have mains electricity supply, so solar is the only option. Whatever I do will be a temporary measure, as I plan to build a large workshop/log milling area next year with mains electricity.

I've seen this system on Amazon:
40w solar panel and controller

I already have this battery for a garden sprayer:
12v / 9ah battery

Would the 40w panel and 9ah battery be sufficient to run two 12v computer fans, such as:
12v DC computer fan

Many thanks!

 

[MisterSandals]

Fans show .45A at 12V
40W panel / 12V = 3.3A

(9Ah battery / (2x .45)) x .5 (50% usable) = 5h runtime from battery

My guess is that your fans would run in full sun 5 hours a day while charging battery Then possibly, with a good battery and full charge up to 5 more hours.

It is barely sized big enough for even this.

 

[BradCagle]

If you know someone that works in roofing, they regularly replace roofs that have solar vent/fans. They toss them. You might ask if they would keep you a couple.

I use them in my solar shed, and they sip power.

 

[backwoods]

Look into the turbine roof vent aka whirlybird vents.
Only requires wind to extract air. Of course you need to still add an inlet but completely passive.
You could put your powered fans on a humidistat and when wind is lacking they pick up the slack.

 

[BradCagle]

Look into the turbine roof vent aka whirlybird vents.
Only requires wind to extract air. Of course you need to still add an inlet but completely passive.
You could put your powered fans on a humidistat and when wind is lacking they pick up the slack.

Those can work if you have a breeze.

The salvaged solar fans I use run as low as 1w. I have a little buck converter on it so I can adjust the voltage.

 

[backwoods]

Those can work if you have a breeze.

The salvaged solar fans I use run as low as 1w. I have a little buck converter on it so I can adjust the voltage

I did say when the wind is lacking, but it doesn't take much for them to move, even the temp difference can make them spin.
personally don't care, what anyone uses, it is a energy free solution.